题目

When it comes to medical care, many patients and doctors believe “more is better.” But what they do not realize is that overtreatment—too many scans, too many blood tests, too many procedures—may bring harm. Sometimes a test leads you down a path to more and more testing, some of which may be invasive, or to treatment for things that should be left alone. Terrence Power, for example, complained that after his wife learned she had Wegener's disease, an uncommon disorder of the immune system, they found it difficult to refuse testing recommended by her doctor. The doctor insisted 线粒体是细胞的能量转换器，而叶绿体则不是．××．